GE C70, Instruction Manual

Page: 276 / 708

5-152 C70 Capacitor Bank Protection and Control System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
5.6.4 PHASE CURRENT
a) MAIN MENU
PATH: SETTINGS

GROUPED ELEMENTS

SETTING GROUP 1(6)

PHASE CURRENT
b) INVERSE TOC CURVE CHARACTERISTICS
The inverse time overcurrent curves used by the time overcurrent elements are the IEEE, IEC, GE Type IAC, and I
2
t stan-
dard curve shapes. This allows for simplified coordination with downstream devices.
If none of these curve shapes is adequate, FlexCurves may be used to customize the inverse time curve characteristics.
The definite time curve is also an option that may be appropriate if only simple protection is required.
A time dial multiplier setting allows selection of a multiple of the base curve shape (where the time dial multiplier = 1) with
the curve shape (
CURVE
) setting. Unlike the electromechanical time dial equivalent, operate times are directly proportional
to the time multiplier (
TD MULTIPLIER
) setting value. For example, all times for a multiplier of 10 are 10 times the multiplier 1
or base curve values. Setting the multiplier to zero results in an instantaneous response to all current levels above pickup.
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PHASE CURRENT
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
PHASE TOC1
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See page 5–157.
MESSAGE
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PHASE TOC2

See page 5–157.
↓
MESSAGE
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PHASE TOC6

See page 5–157.
MESSAGE
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PHASE IOC1

See page 5–159.
MESSAGE
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PHASE IOC2

See page 5–159.
↓
MESSAGE
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PHASE IOC12

See page 5–159.
MESSAGE
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PHASE
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DIRECTIONAL 1
See page 5–160.
MESSAGE
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PHASE
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DIRECTIONAL 2
See page 5–160.
MESSAGE
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PHASE CURRENT

UNBALANCE 1
See page 5–163.
MESSAGE

PHASE CURRENT

UNBALANCE 2
See page 5–163.
MESSAGE
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PHASE CURRENT

UNBALANCE 3
See page 5–163.
Table 5–19: OVERCURRENT CURVE TYPES
IEEE IEC GE TYPE IAC OTHER
IEEE Extremely Inverse IEC Curve A (BS142) IAC Extremely Inverse I
2
t
IEEE Very Inverse IEC Curve B (BS142) IAC Very Inverse FlexCurves A, B, C, and D
IEEE Moderately Inverse IEC Curve C (BS142) IAC Inverse Recloser Curves
IEC Short Inverse IAC Short Inverse Definite Time